When a figure is rotated 90^(∘) counterclockwise about the origin, the coordinates of the image's vertices will change in the following way.
(a,b)→ (- b,a)
Using this rule and the vertices of the triangle, we can find the x- and y-coordinates of the rotated point F.
(a,b)
(- b,a)
F(2,1)
F'(- 1,2)
The obtained coordinates correspond to the option C.
